A windshield wiper on a certain model car pivots through an angle of 123°. The total arm and blade length is 24 inches. If the blade is 21 inches, what is the total area of windshield being cleaned by the wiper?

Answer 1

area of a sector is

a = 1/2 r^2 θ
so, the area is

1/2 π(123/180) (24^2-3^2) = 608.6 in^2